[PATCH 5.19 091/101] drm/i915/gt: Perf_limit_reasons are only available for Gen11+

From: Greg Kroah-Hartman
Date: Mon Oct 03 2022 - 03:22:50 EST


From: Ashutosh Dixit <ashutosh.dixit@xxxxxxxxx>

[ Upstream commit 7738be973fc4e2ba22154fafd3a5d7b9666f9abf ]

Register GT0_PERF_LIMIT_REASONS (0x1381a8) is available only for
Gen11+. Therefore ensure perf_limit_reasons sysfs files are created only
for Gen11+. Otherwise on Gen < 5 accessing these files results in the
following oops:

<1> [88.829420] BUG: unable to handle page fault for address: ffffc90000bb81a8
<1> [88.829438] #PF: supervisor read access in kernel mode
<1> [88.829447] #PF: error_code(0x0000) - not-present page

This patch is a backport of the drm-tip commit 0d2d201095e9
("drm/i915: Perf_limit_reasons are only available for Gen11+") to
drm-intel-fixes. The backport is not identical to the original, it only
includes the sysfs portions of if. The debugfs portion is not available
in drm-intel-fixes so has not been backported.

Bspec: 20008
Bug: https://gitlab.freedesktop.org/drm/intel/-/issues/6863
Fixes: fa68bff7cf27 ("drm/i915/gt: Add sysfs throttle frequency interfaces")
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@xxxxxxxxx>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20220919162401.2077713-1-ashutosh.dixit@xxxxxxxxx
(backported from commit 0d2d201095e9f141d6a9fb44320afce761f8b5c2)
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c b/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c
index f76b6cf8040e..b8cb58e2819a 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c
@@ -544,8 +544,7 @@ static INTEL_GT_RPS_BOOL_ATTR_RO(throttle_reason_ratl, RATL_MASK);
static INTEL_GT_RPS_BOOL_ATTR_RO(throttle_reason_vr_thermalert, VR_THERMALERT_MASK);
static INTEL_GT_RPS_BOOL_ATTR_RO(throttle_reason_vr_tdc, VR_TDC_MASK);

-static const struct attribute *freq_attrs[] = {
- &dev_attr_punit_req_freq_mhz.attr,
+static const struct attribute *throttle_reason_attrs[] = {
&attr_throttle_reason_status.attr,
&attr_throttle_reason_pl1.attr,
&attr_throttle_reason_pl2.attr,
@@ -594,9 +593,17 @@ void intel_gt_sysfs_pm_init(struct intel_gt *gt, struct kobject *kobj)
if (!is_object_gt(kobj))
return;

- ret = sysfs_create_files(kobj, freq_attrs);
+ ret = sysfs_create_file(kobj, &dev_attr_punit_req_freq_mhz.attr);
if (ret)
drm_warn(&gt->i915->drm,
- "failed to create gt%u throttle sysfs files (%pe)",
+ "failed to create gt%u punit_req_freq_mhz sysfs (%pe)",
gt->info.id, ERR_PTR(ret));
+
+ if (GRAPHICS_VER(gt->i915) >= 11) {
+ ret = sysfs_create_files(kobj, throttle_reason_attrs);
+ if (ret)
+ drm_warn(&gt->i915->drm,
+ "failed to create gt%u throttle sysfs files (%pe)",
+ gt->info.id, ERR_PTR(ret));
+ }
}
--
2.35.1